Lactone compounds derived from pyridine-carboxylic acids and process for preparing the same

ABSTRACT

ARE AS DEFINED HEREINAFTER, USEFUL AS A COLOR FORMER, AND A PROCESS FOR PREPARING THE SAME ARE DISCLOSED. A lactone compound represented by the following formula   OR A MIXTURE THEREOF, WHEREIN R1, R2, R3 and the partial structure

United States Patent [1 1 Ozutsumi et al.

[ LACTONE COMPOUNDS DERIVED FROM PYRlDINE-CARBOXYLIC ACIDS AND PROCESS FOR PREPARING THE SAME [75] Inventors: Minoru Ozutsumi; Yoshihide Miyazawa; Susumu Suzuka, all of Tokyo, Japan [73] Assignee: Hodogaya Chemical Co., Ltd.,

Tokyo, Japan [22] Filed: Mar. 25, 1974 [2]] Appl. No.: 454,526

OTHER PUBLICATIONS Michio et al., Benzofluoran pressure sensitive dyes" in Chem. Abs, Vol. 75, 1971,7430x.

Primary Examiner-Allen B. Curtis Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A lactone compound represented by the following formula 1 July 22, 1975 1 /0 o I c l\N O R; @C jg (lb) or a mixture thereof, wherein R,, R R and the partial structure are as defined hereinafter, useful as a color former, and a process for preparing the same are disclosed.

9 Claims, No Drawings LACTONE COMPOUNDS DERIVED FROM PYRIDINE-CARBOXYLIC ACIDS AND PROCESS FOR PREPARING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to novel lactone compounds and a process for preparing the lactone compounds. more particularly, this invention relates to novel lactone compounds of the formula represents a naphthalene residual group of the formula (lVa) or (IVb) (Iva) (IV'b) wherein R represents a hydrogen atom. a lower alkyl group, a lower alkoxy group, a halogen atom, an amino group, a mono-lower alkylamino group. di-lower alkylamino group, a monobenzylamino group, a dibenzylamino group, an N-lower alkyl-Nbenzylamino group, an aniline group, an N-lower alkylanilino group, a -NHCO-X group wherein X represents a lower alkyl group, a lower alkenyl group, or an unsubstituted or substituted styryl group, an unsubstituted or substituted phenyl group or an unsubstituted or substituted naphthyl group wherein the substituent is a lower alkyl group, a lower alkoxy group, a di-lower alkylamino group, a hydroxy group, a nitro group or a halogen atom, wherein the lower alkyl, alkoxy and alkenyl groups have l to 5 carbon atoms, and a process for preparing such lactone compounds. The lactone compounds of this invention are useful as color formers since they are essentially colorless but are capable of developing various colors upon heating or contact with acidic substances.

2. Description of the Prior Art Hithertofore, the known color formers of this type include Crystal Violet lactones, Malachite Green lactones, rhodamine lactam derivatives, leuco-auramine derivatives, leuco-methylene blue derivatives and indolino-spiropyrane derivatives, leucoauramine compounds of bis(p-substituted aminoaryl)-methane or quaternarized or sulfonated derivatives thereof. However, these well-known compounds have various disadvantages such as a slow color developing rate, a low density of colors, poor light-resistance and weatherresistance of the developed colors and color changes with the lapse of time. Also, these known color formers sometimes shows bleeding of the developed colors and tend to develop colors or to decrease an ability to develop colors during the storage of the color formers.

SUMMARY OF THE INVENTION An object of this invention to provide novel lactone compounds derived from pyridine-carboxylic acids as color formers which are, per se, substantially colorless but are capable of developing various colors.

Another object of this invention is to provide novel color formers which are stable against sun-light, moisture, oxygen, etc. without easily causing any decomposition or color-development during the storage but are capable of developing various colors rapidly and in high density upon heating or contact with acidic substances thereby producing colors having excellent light-fastness and weather-resistance.

A further object of this invention is to provide a process for preparing such novel lactone compounds de-. rived from pyridine-carboxylic acids.

DETAILED DESCRIPTION OF THE INVENTION The lactone compounds derived from pyridinecarboxylic acids of this invention represented by the formula (la) or (lb) (lb) n RZ/ l A C l N C=O k wherein R R R and the partial structure of are as defined above, can be prepared by condensing a benzoyl-pyridine-carboxylic acid represented by the formula (Ila) or (llb) (11a) 0R coon -co R /N (llb) QR1+ coon wherein R R and R are as defined above. and R, represents a hydrogen atom or a lower alltyl group. with a naphthalene compound represented by the formula (III) wherein R represents a hydrogen atom or a lower alkyl group and the -OR group is substituted on lor 2- position of the naphthalene ring, and R is as defined above.

Alternatively, the pyridine-carboxylic acid lactones of this invention represented by the formula (Vllla) or (Vlllb) (VIIIa) (VIIIb) wherein R R and R are as defined above, and the partial structure represents a residue of a naphthalene compound of the formula (lXa) or (lXb) mice-x (Lia) (IXb) wherein X is as defined above, can be prepared by condensing a pyridine-carboxylic acid lactone, which is prepared by the above-described process, represented wherein R R and R are as defined above. and the partial structure represents naphthylamine of the formula (VIa) or (VIb) (Vla) (Vlb) with an acid halide represented by the formula (VII) wherein X is as defined above and Y represents a halogen atom.

The lactone of the present invention is a substantially colorless or slightly colored powder which is stable in atmosphere but undergoes changes in its color to red, purplish red, reddish purple, blue or dark reddish brown by heating. The Iactones of this invention as color formers are soluble in or miscible with high molecular weight substances such as animal, vegetable or mineral waxes, ethyl cellulose, polyvinylacetate, rosinmodified alkyd resins and are soluble in a wide variety of organic liquids such as methanol, ethanol, ethyl cellosolve, chloroform, benzene, toluene, chlorobenzenes, alkylnaphthalenes, tri-octylphosphate and the like. The solution of the lactones of this invention in the above organic liquid develop a red, purplish red, reddish purple, blue or dark reddish brown color immediately after the solution is adsorbed on active clay substances such as acid clay, attapulgite, zeolite, bentonite and the like. solid organic acids such as succinic acid, maleic acid, tannic acid, benzoic acid and the like, or acidic polymers such as carboxypolyethylene, phenol-aldehyde polymers, styrene-maleic anhydride copolymers containing residual acidic groups. The color developed on such solid materials generally has a high color density and is characterized by excellent moisture-resistance and light-fastness. Thus, the Iactones of this invention are useful as marking color formers for the recording materials such as heat-sensitive copying papers, hectographical printing papers, pressure-sensitive copying papers.

Representative compounds of the benzoyl-pyridinecarboxylic acid represented by the formulae (Ila) and (IIb) used in the present invention are 3- and 2-[2'-oxy- 4'-diethylaminobenzoyl]-pyridine-carboxylic acid-( 2) and -(3); 3- and 2-[2'-methoxy-4'-dimethylaminobenzoyl}-pyridine-carboxylic acid-(2) and -(3); 3- and 2-[2-ethoxy-4'-diethylamino-benzoyll-pyridinecarboxylic acid-(2) and -(3); 3- and 2-[2'-methoxy-4'- (N-methyl-N-benzyl)-aminobenzoyll-pyridinecarboxylic acid-(2) and -(3); 3- and 2-[2-methoxy-4'- dibenzylamino-benzoyl[ -pyridine-carboxylic acid-( 2) and -(3); 3- and 2-[2'-oxy-4'-benzyIamino-benzoyl]- pyridine-carboxylic acid-(2) and -(3)', 3- and 2-[2'- oxy-4-aniIino-benzoyll-pyridine-carboxylic acid-(2) and -(3); 3- and 2-[2'-methoxy-4'-(N-methyI-N- phenyl)-arnino-benzoyl]- pyridine-carboxylic acid-(2) and -(3 3- and 2-[2'-oxy-4'-(4"-methyl)-anilinobenzoyll-pyridine-carboxylic acid-(Z) and -(3); 3- and 2-[2'-oxy 4'-(4"-chloro)-anilino-benzoyll-pyridinecarboxylic acid-(2) and -(3); 3- and 2-[2'-ethoxy-4'- (VII) 6 diethylamino-benzoyl]-4-methyl-pyridine-carb0xylic acid-(2) and -(3); 3- and 2-[2'-ethoxy-4'-diethylaminobenzoyl]-4-chloro-pyridine-carboxylic acid-(2) and -(3); 3- and 2-[2'-ethoxy-4'-diethylamino-benzoyl1-6- phenylpyridine'carboxylic acid-(2) and -(3); and the like.

Representative compounds of the naphthalene compounds represented by the formula (III) used in the process of this invention are Z-naphthol, 6-n-butyl-2- naphthol, fJ-methoxy-l-naphthol, 6-bromo-2-naphthol, S-amino-Zmaphthol, 8-amino-2-naphthol, 5- ethyIamino-Z-naphthol, 5-dimethylamino-Z-naphthol, S-diethyIamino-Z-naphthol, 8-diethylamino-2- naphthol, 5-dibenzylamino2-naphthol, S-(N-methyl- N-benzyl)-amino-2-naphthol. S-anilino-Z-naphthol. 8 anilino-Z-naphthol, l-naphthol, 4-ethoxy-l-naphthol 4-amin0- l -naphthol, S-aminol -naphthol, 4-dimcthylamino-l-naphthol, S-dimethylamino-l-naphthol, S-diethylaminol -naphthol, 4-benzylaminol naphthol, S-benzylamino-l-ethoxy-naphthalene, S-(N- methyl-N-benzyl )-aminol -methoxy-naphthalene, 4- anilinol -naphthol, S-dimethylamino-2-methoxynaphthalene, 4-(N-methyl-N-phenyl)-amino-lmethoxymaphthalene, 5-(N-methyl-N-phenyl)-aminol-naphthol, 5-acetamido-lnaphthol, 5-acetamio-2- naphthol, 4-acetamido-l-naphthol, 8-acetamido-2- naphthol, S-acetamidol -methoxy-naphthalene, S-propionamido-Z-naphthol, -propionamido-l-naphthol, 7-propionamidol -ethoxy-naphthalene, 8-butylamido- Z-naphthol, 5 -acrylamidol -naphthol, S-cinnamamido-l-naphthol, S-(4'-chloro)-cinnamamido-2- naphthol, S-benzamido-Z-naphthol, 4-benzamidol naphthol, S-benzamidol -naphthol, S-benzamido-Z- naphthol, S-benzamido-Z-naphthol, 7-benzamidol methoxy-naphthalene. 5-( 4'-methyl )-benzamidol naphthol, 5-(4'-methyl)-benzamido-2-naphthol, 4-(2- methyI-benzamidol -naphthol, 8-( 3 -methyl benzamidol -methoxy-naphthalene, 5-(4'-ethyl benzamidol-methoxy-naphthalene, 5-( 2 '.4

dimcthyl l-benzamido-Z-naphthol, 5-( 4 '-methoxy benzamido-l-naphthol, 5-(2'-methoxy)-benzamido-2- naphthol, 4-(2'-ethoxy)-benzamidolnaphthol. 8-( 2'- ethoxy)-benzamido-2-naphthol, 5-(4"chloro)-benzamidol -naphthol, 5-( 4 '-chloro )-benzamido-2- naphthol, 4-(4'-bromo)-benzamido-l-naphthol, 8-( 2- chloro)-benzamido-2-naphthol, S-( 2 ',4'-dichloro benzamido-2-naphthol, 5-( 3 '-chloro-4'-methyl )-ben- Zamido-I-naphthol, 5-(4'-dimethylamino)-benzamidol-methoxy-naphthalene, 5-(4'-nitro)-benzamido-2- naphthol, 4-(2 ',4'-dinitro )-benzamidol -methoxynaphthalene, 5-(4-oxy)-benzamido-2-naphthol, 7- (2',4-dioxy)-benzamidol -naphthol, 5-( 3'-methoxy-4' -oxy)-benzamido-l-naphthol, 5-( l '-naphthoyl)-aminol-naphthol, 5-( 2'-naphthoyl)-amino-2-naphthol, 5-( 5 methyl-I '-naphthoyI)-amino-l-naphthol and the like.

The benzoyl-pyridine-carboxylic acids represented by the formula (Ila) or (llb) above can be prepared by one of the following procedures (1 to (4):

1. quinolinic anhydride is reacted with an aniline compound corresponding to the desired benzoyI-pyridine-carboxylic acid represented by the formula (Ila) or (llb) in a volatile inert organic solvent such as carbon disulfide, carbon tetrachloride, tetrachloroethane, benzene, chlorobenzene, nitrobenzene or the like using a Friedel-Crafts catalyst such as Zinc chloride, phosphorus chloride,

aluminum chloride or the like at a temperature of from l to l C for a period of from about 1 to 9 hours. 2. quinolinic anhydride is reacted with an aniline compound corresponding to the desired benzoyl-pyridine-carboxylic acid represented by the formula (Ila) or (llb) in a condensing agent such as concentrated sulfuric acid, phosphoric acid, polyphosphoric acid or the like at a temperature of from about 30 to 120C for a period of from 2 to 8 hours.

3. quinolinic anhydride is reacted with an aniline compound corresponding to the desired benzoyl-pyridine-carboxylic acid represented by the formula (lla) or (llb), optionally in an inert organic solvent as those described above (1) at a temperature of from 100 to l80C for a period of from 2 to l0 hours.

4. quinolinic acid is reacted with sulfuryl chloride, phosphorus pentachloride or the like to produce quinolinic acid chloride which is then reacted with an aniline compound corresponding to the desired benzoyl-pyridine-carboxylic acid represented by the formula (Ila) or (llb) in the organic insert solvent as those described above using a Friedel- Crafts catalyst.

Of these alternative procedures, a particularly preferred procedure is that described in l above and this procedure is illustrated hereinbelow in greater detail.

1 mole of quinolinic anhydride, 0.9 to 2.0 moles, preferably 1.0 to 1.5 moles of an aniline compound corresponding to the benzoyl-pyridine-carboxylic acid represented by the formula (lla) or (llb) and 1.0 to 3.0 moles, preferably 1.0 to moles of a Friedel-Crafts catalyst are added to 0.5 to 2.5 liter of the above described volatile organic inert solvent, and the resulting mixture is allowed to react at a temperature of from about l0 to ll0C for a period of from about 1 to 9 hours. The resulting reaction mixture is then cooled to room temperature, and a crystalline isomer mixture comprising a 3-benzoyl-pyridine-carboxylic acid-(2) and a 2-benzoyl-pyridinecarboxylic acid-(3) represented by the formulae (Ila) and (llb) can be recovered from the reaction mixture by either the following (1) or (2):

l. The reaction product obtained by removing the solvent by decantation is added to about 2 to 6 liter of ice-water or a cold dilute aqueous hydrochloric acid to decompose any remaining catalyst used. The precipitated solid is then filtered, washed successively with water and an alcohol or benzene and dried.

2. The reaction product obtained as above (1) is added to about 2 to 6 liter of ice-water to decompose any remaining catalyst used, and an additional portion of the organic inert solvent as described above is added to the aqueous mixture to transfer the reaction product into the organic solvent layerv The organic solvent layer is then separated and the solvent is distilled off to leave the reaction product as a residue.

Also, if desired, the above isomer mixture can be sepdroxide, adding dilute aqueous hydrochloric acid to the resulting solution in small portions and separately recovering the solid which precipitates due to the difference in pH of the solution, (2) repeatedly recrystallizing the isomer mixture from a solvent mixture of a less polar solvent such as benzene, toluene and the like and a polar solvent such as methanol, butanol and the like, or (3) a combination of l) and (2) above.

The pyridine-carboxylic acid lactones of this invention represented by the formula (la) or (lb) above can be prepared as follows. In the preparation of these pyridine-carboxylic acid lactones, the benzoyl-pyridinecarboxylic acids used herein represented by the formula (lla) or (llb) are those prepared as described above and two isomers in the resulting benzoyl-pyridine-carboxylic acids may be present therein in any proportion. That is, benzoyl-pyridine-carboxylic acids which can be used in the preparation of the pyridine carboxylic acid lactones include a highly purified 2-benzoyl-pyridine-carboxylic acid-(3) or a highly purified 3-benzoyl-pyridine-carboxylic acid-(2), an isomer mixture comprising predominantly a 3-benzoyl-pyridine-carboxylic acid-(2) and a small amount of a 2-benzoyl-pyridine-carboyxlic acid-(3) or vice versa or any other isomer mixtures in which a 3-benzoyl-pyridinecarboxylic acid-(2) and a 2-benzoyl-pyridine-carboxylic acid(3) are present in optional proportions.

The pyridine-carboxylic acid lactones can be prepared by reacting a benzoyl-pyridinc-carboxylic acid represented by the formula (Ila) or (llb) above with a naphthalene compound represented by the formula (III) in the presence of a condensing agent. If desired, a volatile inert organic solvent such as chloroform, tetrachloroethanc, benzene, chlorobenzenes or the like can be employed as a solvent in order to ensure smooth proceeding of the condensation reaction. The condensing agent which can be used includes concentrated sulfuric acid, acetic anhydride, phosphorus pentachloride, phosphorus oxychloride, phosphoric acid, polyphosphoric acid, zinc chloride, stannic chloride. aluminum chloride or the like. Of these condensing agents, concentrated sulfuric acid or polyphosphoric acid is preferably employed because it serves not only as a condensing agent but also as a reaction solvent. The process for preparing these lactones according to the present invention is illustrated below in greater detail.

One mole of the benzoyl-pyridine-carboxylic acid represented by the formula (lla) or (llb) and 1.0 to 1.5 moles, preferably L0 to L2 moles, of the naphthalene compound represented by the formula (III) are added to about 3 to 30 moles of concentrated sulfuric acid or polyphosphoric acid, and the resulting mixture is allowed to react at a temperature of about 30 to C for a period of from about 2 to [0 hours. The reaction product is then poured into about l to 5 liters of icewater to hydrolyze or dilute the condensing agent, and the resulting aqueous solution is made weakly acidic or neutral with dilute aqueous sodium hydroxide. Benzene or toluene is added thereto followed by stirring to transfer any unreacted naphthalene compound to the benzene or toluene layer, which is then removed by separation. The residual aqueous layer is adjusted to a pH ranging from about l l to l2 with dilute aqueous sodium hydroxide and the precipitated solid is filtered, washed successively with water and a small amount of petroleum ether or an alcohol and dried to obtain a lactone compound of the pyridine'carboxylic acid represented by the formula (la) or (lb) as substantially colorless or slightly colored crystals in high yield. Alternatively, the residual aqueous layer as above obtained after removal of the benzene or toluene layer is adjusted to a pH of l l to l2 with dilute aqueous sodium hydroxide, and benzene or toluene is added to the resulting aqueous solution followed by stirring to transfer the lactone compound of pyridine-carboxylic acid to the benzene or toluene layer which is then recovered by separation. The benzene or toluene is distilled off from the benzene or toluene layer to obtain a residue which is then washed successively with water and a small amount of an alcohol or benzene and dried to obtain a lactone compound of pyridine-carboxylic acid represented by the formula (la) or (lb) as substantially colorless or slightly colored crystals in high yield. If desired, the above obtained lactone compound of pyridine-carboxylic acid can be recrystallized from an appropriate solvent.

Representative compounds of the present invention represented by the formula (Va) or (Vb) are 3- and 2- [3'-dimethylamino-7 '-amino-benzo(c)-l l '-oxyxanthenyll-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3-diethylamino-7'-amino-benzo(c)- l1'-oxy-xanthenyll-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3'-diethylamino-l0'-aminobenzo(c)-l l'-oxy-xanthenyll-pyridine-carboxylic acid- (2) and -(3) lactone; 3- and 2-[3'-ethylamino-8-. amino-benzo(a)-l l '-oxy-xanthenyll-pyridinecarboxylic acid-(2) and -(3) lactone; 3- and 2-[3'- diethylamino-S'-amino-benzo(a)-l l '-xanthenyl]-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[ 3- diethylamino-9'-amino-benzo(a)-l l '-oxy-xanthenyl]- pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[ 3'-dibenzylamino-7 '-amino-benzo(c )-l l '-oxyxanthenyll-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3'-dibenzylamino-8'-amino-benzo(a)- ll-oxy-xanthenyl]-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3' -anilino-7-amino-benzo(c)- ll'-oxy-xanthenyll-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3-(N-methyl-N-phcnyl)-amino- 7'-amino-benzo(c)-l l -oxy-xanthenyl]-pyridinecarboxylic acid-(2) and -(3) lactone; 3- and 2-[3'-(N- methyl-N-phenylamino-S'-amino-benzo(a)-l l'-oxyxanthenyl]-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[(3'-(N-ethyl-N-phenyl)-amino-9'- amino-benzo(a)-l l'-oxy-xanthenyl]-pyridinecarboxylic acid-(2) and -(3) lactone; 3- and 2-[3'-N- methyl-N-(4"-methyl)-phenylamino-8'-aminobenzo(a)-l l-oxy-xanthenyll-pyridine-carboxylie acid- (2) and -(3) lactone; 3- and 2-[3'-N-methyl-N-(4"- chloro )-phenyl-amino-7'-amino-benzo(c)-l l '-oxyxanthenyll-pyridine-carboxylic acid-(2) and -(3) lactone; 3- and 2-[3'-diethylamino-7'-amino-benzo(c)- l l'-oxy-xanthenyl1-4-methyl-pyridine-carboxylic acid- (2) and -(3) lactone; 3- and 2-[3'-diethylamino-7'- aminobenzo(c)-l l '-oxy-xanthenyll-4-chloro-pyridinecarboxylic acid-(2) and -(3) lactone; 3- and 2-[3- diethylamino-S'-amino-benzo(a)-l l'-oxy-xanthenyl]- 4-chloro-pyridine-carboxylic acid-(2) and -(3) lactone, 3- and 2-[ 3-diethylamino-7-amino-benzo(c)-1 l'-oxyxanthenyl]-6-phenyl-pyridine-carboxylic acid-(2) and -(3) lactone and the like.

Representative compounds of the acid halide represented by the formula (Vll) are acetyl chloride, propionyl chloride, butyryl chloride, acryloyl chloride, benzoyl chloride, 2-toluoyl chloride, 4-toluoyl chloride, 2,4-dimethyl-benzoyl chloride, 2-methoxy-benzoyl chloride, 2,4-diethoxy-benzoyl chloride, 3- dimethylamino-benzoyl chloride, 4-diethylaminobenzoyl chloride, 4-oxy-benzoyl bromide, 3,4.5-trioxybenzoyl chloride, 4-nitro-benzoyl chloride, 2-chlorobenzoyl chloride, 4-bromo-benzoyl bromide, 2,4- dichloro-benzoyl chloride, 2-mcthyl-5-chloro-benzoyl chloride, cinnamoyl chloride, 4-chloro-cinnamoyl chloride, 4-dimethylamino-cinnamoyl chloride, 1- naphthoyl chloride, Z-naphthoyl chloride, 1-oxy-2- naphthoyl chloride and the like.

The pyridine-carboxylic acid lactone compounds represented by the formula (Vllla) or (Vlllb) can be prepared by reacting a pyridine-carboxylic acid lactone represented by the formula (Va) or (Vb) with an acid halide represented by the formula (Vlll) in a volatile inert organic solvent such as chloroform, benzene, toluene, chlorobenzenes or the like in the presence of an acid acceptor, for example, volatile organic basic compounds such as triethylamine, pyridine, dimethylaniline or the like or water-soluble inorganic basic compounds such as sodium bicarbonate, sodium carbonate or the like, preferably in the presence of a volatile organic basic compound. In a preferred embodiment, l.0 mole of a pyridine-carboxylic acid lactone represented by the formula (Va) or (Vb) is dissolved in a mixture of about 0.3 to L0 liter of the above volatile inert organic solvent and L0 to 1.5 moles of the above volatile organic basic compound, and 1.0 to 1.5 moles of an acid halide represented by the formula (Vll) is added to the resulting solution. After allowing the resulting mixture to react for 2 to 8 hours at a temperature of from 40 to C. the reaction mixture is allowed to cool to room temperature and washed with water. The volatile inert organic solvent is then distilled off and the resulting residue is washed with a small amount of an alcohol, petroleum ether or ligroin and dried to obtain a lactone compound of the pyridine-carboxylic acid represented by the formula (Vllla) or (Vlllb) in high yield as substantially colorless or slightly colored crystals. If desired, the thus obtained pyridine-carboxylie acid lactone can be purified by recrystallization.

The present invention is further illustrated in greater detail by the following Examples, but these Examples are not to be construed as limiting the scope of this invention. All parts, percentages, proportions and the like are by weight unless otherwise indicated.

EXAMPLE 1 [0 g of quinolinie anhydride and 26 g of N,N-diethylr'n-phenetidine were added to 100 ml of benzene, and 27 g of anhydrous aluminum chloride was added to the mixture in small portions over about 20 minutes while stirring and maintaining the temperature at 30 to 35C.

Upon completion of the addition, the mixture was allowed to react for 4 hours at a temperature in the range of from 35 to 38C and thereafter was cooled to room temperature. The benzene was removed by decantation, and the resulting reaction product was added to 300 ml of ice-water followed by stirring. The precipitated solid was filtered, washed with water and dried to give g of an isomer mixture comprising 3-[2'- ethoxy-4-diethylamino-benzoyll-pyridine-carboxylic acid-(2) and 2-[2'-ethoxy-4'-diethylamino-benzoyl]- pyridine carboxylic acid-(3) as pale brown crystals having a melting point of 245 to 253C. 15.5 g of the resulting crystals was then dissolved in dilute aqueous sodium hydroxide. Dilute aqueous hydrochloric acid was added to the solution to adjust the pH to 6 and the precipitated solid was filtered (the filtrate was set aside). washed and dried to give g of an isomer mixture comprising predominantly 3-[2'-ethoxy-4' -diethylamino-benzoyl]-pyridine-carboxylic acid-(2) and a small amount of 2-12-ethoxy-4'-diethylaminobenzoyl]-pyridine-carboxylic acid-(3) as light yellowish brown crystals having a melting point of 293 to 297C. 10 g of the resulting crystals was then recrystallized several times from a mixed solvent of methanolbenzene 1 l by volume) to give 6.5 g of a highly purified 3-[2'-ethoxy-4'-diethylamino-benzoyl]-pyridinecarboxylic acid-(2) as pale yellow crystals having a melting point of 297 to 298C.

The filtrate having a pH of 6 obtained from the filtration of the above product was then adjusted to a pH of about 2 with dilute aqueous hydrochloric acid, and the precipitated solid was filtered. washed with water and dried to give 4 g of an isomer mixture comprising predominantly 2-12'-ethoxy-4'-diethylamino-benzoyl]- pyridine-carboxylic acid-(3) and a small amount of 3- [2'-ethoxy-4'-diethylamino-benzoyll-pyridinecarboxylic acid-(2) as pale brown crystals having a melting point of 176 to 181C.

4 g of the isomer mixture thus obtained was then recrystallized several times from a mixed solvent of methanol-toluene (l 1 by volume) to give 2.3 g of a highly purified 2 [2'-ethoxy-4'-diethylamino-benzoyl1- pyridine-carboxylic acid-(3) as substantially colorless crystals having a melting point of 179 to 180C.

2 g of the above obtained 3-[2'-ethoxy4'- diethylamino-benzoyll-pyridine-carboxylic acid-(2) (m.p., 297- 298C) and 1.2 g of 5-dimethylamino-2- naphthol were added to 18.4 g of 95% sulfuric acid. and the mixture was allowed to react at a temperature of 95 to 100C for 4 hours followed by allowing the mixture to cool to room temperature. The reaction product was then poured into 100 ml of ice-water, and the mixture was adjusted to a pH of about 1 l with dilute aqueous sodium hydroxide. 50 ml of benzene was then added to the resulting aqueous solution to transfer the resulting lactone of pyridine-carboxylic acid to the benzene layer which was then recovered by separation. The benzene was distilled off from the benzene layer, and the residue thus obtained was washed successively with water and a small amount of petroleum ether and dried to give 2.3 g of 3-l3'-diethylamino-7'- dimethylamino-benzo(c)-l 1 '-oxy-xanthenyl]-pyridinecarboxylic acid-(2) lactone as pale white-brown colored crystals having a melting point of 217 to 219C. A solution of the above crystals in benzene showed a purplish blue color immediately after the solution was adsorbed on acid clay. Also, a suspension of the above crystals in polyvinyl acetate developed a purplish blue color immediately after the suspension was heated at a temperature of from 120 to 150C.

g of 2-[2-ethoxy-4-diethylamino-benzoyll-pyridine-carboxylic acid-(3) (m.p., 179- 180C) obtained above and 1.2 g of 5-dimethylamino2-naphthol were added to 18.4 g of 95% sulfuric acid, and the mixture was allowed to react at a temperature of from 95 to 100C for 4 hours followed by cooling to room temperature. The reaction product was poured into 100 ml of ice-water and the mixture was adjusted to a pH of about 11 with dilute aqueous sodium hydroxide while stirring, and 50 ml of benzene was added to the mixture to transfer the resulting lactone of pyridine-carboxylic acid to the benzene layer which was then recovered by separation. The benzene was distilled off from the benzene layer, and the residue thus obtained was washed successively with water and a small amount of petroleum ether and dried to give 2.2 g of 2-[3- diethylamino-7 -dimethylarnino-benzo(c)-l 1 '-oxyxanthenyl]-pyridine-carboxylic acid-(3) lactone as slightly white brown colored crystals having a melting point of 174 to 176C. A solution of the above crystals in benzene developed a purplish blue color immediately after the solution was adsorbed on acid clay.

EXAMPLE 2 4.0 g of the isomer mixture of benzoyl-pyridinecarboxylic acid having a melting point of 245 to 253C as described in Example 1 and 2.0 g of Z-naphthol were added to 40 g of 98% sulfuric acid, and the mixture was allowed to react at a temperature of from to 100C for 4 hours followed by cooling to room temperature. The reaction product was poured into 200 ml of icewater, and the mixture was adjusted to a pH of about 1 1 with dilute aqueous sodium hydroxide. To the mixture was added 100 ml of toluene to transfer the resulting lactone of pyridine-carboxylic acid to the toluene layer, and the toluene layer was recovered by separation. The toluene was distilled off from the toluene layer and the residue thus obtained was washed successively with water and a small amount of petroleum ether and dried to give 2.8 g of a mixture comprising 3-[ 3'diethylamino-benzo(c)-l l'-oxy-xanthenyl]-pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-benzo(c )-l l'-oxy-xanthenyl l-pyridinecarboxylic acid-(3) lactone as slightly pale purplish brown colored crystals having a melting point of to 159C. A solution of the above crystals in toluene developed a reddish purple color immediately after the solution was adsorbed on acid clay.

EXAMPLE 3 2.0 g of the isomer mixture of benzoyl-pyridinecarboxylic acid having a melting point of 245 253C as described in Example 1 and each of naphthalenes (19 compounds listed in Table 1 below) in an amount indicated in the table were added to 20 g of 95% sulfuric acid, and the mixture was allowed to react at a temperature of from 95 to 100C for 4 hours. After completion of the reaction, the reaction product in each instance was worked up in the same manner as described in Example 2 to give the following lactones. (The sample number of the resulting lactone is shown in parentheses) A mixture comprising 3-13'-diethylamino-8'-bromobenzo(c)-l l '-oxy-xanthenyl]-pyridine-carboxylic acid- (2) lactone and 2-[3'-diethy1amino-8-bromohenzo(c)-l 1'-oxy-xanthenyl]-pyridine-carboxylic acid- (3) lactone.

(No. 3-b) A mixture comprising 3-[ 3-diethylamino-8'- methoxy-benzo(c)-1 1 '-oxy-xanthenylI-pyridinecarboxylic acid-(2) lactone and 2-[3'-diethylamino-8'- methoxy-benzo(c)-1 1 '-oxy-xanthenyl]-pyridinecarboxylic acid-(3) lactone.

Table l-Continued Sample Naphthalene Compound Amount Yield Melting Color or Color No. Point Crystals Developed (g) (g) (C) No.3-n 5-Amino-1-naphthol 1.5 1.5 237-243 pale yellow dark reddish brown No.3-o S-Dimethylamino-l-naphthol 1.3 1.9 186-192 pale brown dark reddish brown No.3-p S-Anilino-l-naphthol 1.7 2.0 173-178 pale brown dark reddish brown No.3-q 4-Benzylaminol-naphthol 1.8 1.6 pale yeldark green lowish green No.3r 4-Dimethylamino-l-naphthol 1.3 1.8 162-169 pale pink green N035 4-( N-Methyl'NphenyH- 1.8 1.3 154-161 pale green dark green amino- 1 naphthol EXAMPLE 4 7.0 g of quinolinic anhydride and 14.0 g of N-methyl-N-phenyl-m-anisidine were added to 80 ml of benzene, and 18.8 g of anhydrous aluminum chloride was added to the mixture over minutes at a temperature of from 20 to 34C while stirring. After completion of the addition, the mixture was allowed to react at a temperature of from 45 to 50C for 4 hours followed by cooling to room temperature, and the hem zene was removed by decantation. The precipitated solid was then filtered, washed with water and dried to give 13.6 g of an isomer mixture comprising 3-12- methoxy-4'-(N-methyl-N-phenyl)-amino-benzoyl]- pyridine-carboxylic acid'(2) and 2-12'-methoxy-4'-(N- methyl-N -phenyl )-amino-benzoyl ]-pyridine-carboxylic acid-(3) as pale brown colored crystals having a melting point of 205 to 217C. The crystals were recrystallized. if necessary.

36 of the above isomer mixture of benzoyl-pyridinecarboxylic acids (m.p.. 205-2l'7C) and 2.4 g of 5-dimethylamino-2-naphthol were added to 17 g of 95% sulfuric acid, and the mixture was allowed to react at a temperature of from 95 to 100C for 4 hours followed by allowing the mixture to cool to room temperature. The reaction product was then poured into 200 ml of ice-water, and the mixture was adjusted to a pH of about 12 with dilute aqueous sodium hydroxide while stirring. 100 ml of benzene was added to the mixture to transfer the resulting lactone of pyridinecarboxylic acid, and the benzene was recovered by separation. The benzene was then distilled off from the benzene layer and the residue thus obtained was washed successively with water and a small amount of petroleum ether and dried to give 2.3 g of an isomer mixture comprising 3-[ 3 (N methyl-N-phenyl)-amino- 7'-dimethylamino-benzo(c)-1 l-oxy-xantheny1]-pyridine-carboxylic acid-(2) lactone and 2-[3'-(N-methyl- N-phcnyll-amino'!-dimethylamino-benzo(c)-l l '-oxyxanthenyl Lpyridine-carboxylic acid-(3) lactone as plae purple colored crystals having a melting point of 183 to 190C. A solution of the above crystals in benzene developed a reddish purple color immediately after the solution was adsorbed on acid clay.

EXAMPLE 5 5.0 g of quinolinic anhydride and 14.2 g of N,N-dibenzyl-m-anisidine were added to 60 ml of benzene. and 15.3 g of anhydrous aluminum chloride was added to the mixture over 20 minutes at a temperature of from 20 to 35C while stirring. After completion of the addition, the mixture was allowed to react at a temperature of from 45 to 50C for 5 hours. After the reaction was completed, the reaction mixture was worked up in the same manner as described in Example 4 to give 10.8 g of an isomer mixture comprising 3-[2'- methoxy-4'-dibenzylamino-benzoyll-pyridinecarboxylic acid-(2) and 2-[2'-methoxy-4- dibenzylaminobenzoyl ]-pyridinecarboxylic acid-(3) as pale brown colored crystals having a melting point of from 195 to 203C. The crystals were recrystallized, if

necessary.

4.5 g of the above isomer mixture of benzoyl-pyridine-carboxylic acids (m.p., 195203C) and 1.8 g of 2-naphthol were added to 25 g of sulfuric acid, and the mixture was allowed to react at a temperature of from 1 10 to 120C for 6 hours followed by working up in the same manner as described in Example 4 to give 4.8 g of an isomer mixture comprising 3-[3'- dibenzylamino-benzo(c)-1 1 -oxy-xanthenyl]-pyridinecarboxylic acid-(2) lactone and 2-[3'-dibenzy1aminobenzo(c )-l 1'-oxy-xanthenyll-pyridine-carboxylic acid- (3) having a melting point of 167 to 172C. A solution of the above crystals in toluene developed a red color immediately after the solution was adsorbed on acid clay.

EXAMPLE 6 4.5 g of the isomer mixture of benzoyl-pyridinecarboxylic acid having a melting point of 195 203C as described in Example 5 and each of the naphthalenes listed in Table 2 below in an amount indicated in the table were added to 25 g of sulfuric acid, and the mixture was allowed to react at a temperature of from 95 to C for 4 hours. After completion of the reaction, the reaction product in each instance was worked up in the same manner as described in Example 4 to give the following lactones. (The sample number of the resulting lactone is shown in parentheses) A mixture comprising 3-l3'-dibenzy|aminobenzo(a)-1 1 -oxy-xanthenyll-pyridine-carboxylic acid- (2) lactone and 2-[3'-dibenzylamino-benzo(a)-l l oxy-xanthenyl ]-pyridine-carboxylic acid-( 3) lactone. (No. 6-b) A mixture comprising 3-[3'-dibenzylamino-7'- dimethylamino-benzo(c )-l l '-oxy-xanthenyl l-pyridinecarboxylic acid-(2) lactone and 2 [3'-dibenzylamin0- 7'-dimethy1amino-benzo(c)-1 l '-oxy-xanthenyl]-pyridine-carboxylic acid-(3) lactone.

(No. 6-c) A mixture comprising 3-[3'-dibenzylamino-8'- dimethylamino-benz0( a)-l 1'-oxy-xanthenyl ]-pyridinecarboxylic acid-(2) lactone and 2-[3-dibenzylamino- 8'-dimethylamino-benzo(a)-1 1 -oxy-xanthenyl l-pyridinecarboxylic acid-(3) lactone.

(No. 6-a') A mixture comprising 3-[3'-dibenzylamino-8'-(N methyl-N-benzyl)-amino-benzo(a)-l l '-oxyxanthenyll-pyridine-carboxylic acid-(2) lactone and 2-[ 3 '-dibenzylamino-8 N-methyl-N-benzyl )-aminobenzo(a)-l l-oxy-xanthenyll-pyridine-carboxylic acid 18 4-chloro-quinolinic anhydride, (b) 4-methyl-quinolinic anhydride or (c) o-phenyl-quinolinic anhydride in place of quinolinic anhydride was reacted with N.N-diethyl-m-phenetidine to obtain the correspond- (3) lactone. 5 ing pyridine-carboxylic acid, i.c., (a): an isomer mix- Table 2 Sample Naphthalene Compound Used and Amount Yield Melting Color of Color No. Point Crystals Developed (g) (g) ("Cl No.64! l Naphthol 1.8 3.5 330-238 pale pink red No.6-b 5-Dimethylamino-Z-naphthol l 9 4.2 174-l79 pale purplish purple blue Noifi-c S-Dimethylamino-l-naphthol 1.9 4.4 l93-20l pale brown dark reddish h No.6-d 5-(N-Methyl-N-benzyl)-amino- 2.4 3. pale brown d$eddish I -napthol brown EXAMPLE 7 ture comprising 3-(2'-ethoxy-4'-diethylamino- In the same manner as described in Example beflzoyl)'4 ciflqro-pyndinecarboxYlic acid-(2) i 2' quinolinic anhydride was reacted with 3-(4'-chloro)- Q i q Q -PY anilinmphenoh 3 (4i methyl) anilino phcnol or dine-carboxyhc acid-(3); (b) an lsomer mixture combenzylamino-phenol in place of N-methyl-N-phenyl-mpnsmg I w q a anisidine to obtain the corresponding pyridine mlethyl'pyndfnecmboxyhc acldul f gcarboxylic acid. i.e., an isomer mixture comprising 3- 4 y f ly 'py 1 i l] idi carboxylic ac1d( 3); (c) an isomer mixture comprising carboxylic acid-(2) and 2-l2'-oxy-4'-(4"-chloro)- y-i'* i y 'P 'Y PY anilino-benzoyll-pyridine-carboxylic acid-(3), an isol Q y and met mixture comprising l l n diethylamino-ben zoyl)-6-phenyl-pyr dine-carboxylic anilino-benzoyll-pyridine-carboxylic acid-(2) and 2- respecnvely- The above mixture of [2'-oxy-4'-( 4' '-methyl i-anilino-benzoyl 1 -pyridinecarboxylic acid-(3) or an isomer mixture comprising 3-( 2 '-oxy-4 '-benzylamino-be nzoyl )-pyridinecarboxylic acid-(2) and 2-(2'-oxy-4-benzylaminobenzoyl)-pyridine-carboxylic acid-(3). respectively. The above isomer mixture of benzoyl-pyridinecarboxylic acids was then reacted with Z-naphthol in the same manner as described in Example 4 followed by working up the resulting reaction product to obtain the corresponding pyridine-carboxylic acid lactones in each case.

(No. 7-a) A mixture comprising 3-[ 3'-(4"-chloro)-anilinobenzo(c)-l l'-oxy-xanthenyl]-pyridine-carboxylic acid- (2) lactone and 2-[3'-(4"-chloro)-anilinobenzo(c)- ll'-oxy-xanthenyl]-pyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a red color immediately after the solution was adsorbed on acid clay.

A mixture comprising 3-[3'-methyl)-anilinobenzo(c)-l l-oxy-xanthenyll-pyridine-carboxylic acid- (2) lactone and 2-[3'-(4"methyl)-anilino-benzo(c)- ll'-oxy-xanthenyl]-pyridine-carboxylic acid-(3) lactonei A solution of this mixture in benzene developed a red color immediately after the solution was adsorbed on acid clay.

(No. 7-c) A mixture comprising 3-[3'-benzylamino-benzo(c)- ll-oxy-xanthenyll-pyridine-carboxylic acid-(2) lactone and 2-[ 3 '-benzylamino-benzo(c)-1 l '-oxyxanthenyl]-pyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a red color immediately after the solution was adsorbed on acid clay.

EXAMPLE 8 In the same manner as described in Example 4, (a)

benzoyl-pyridine-carboxylic acids was then reacted with 5-dimcthylamino-Z-naphthol in the same manner as described in Example 4 followed by working up the resulting reaction product to obtain the corresponding pyridine-carboxylic acid lactones in each case.

(No. 8-a) A mixture comprising 3-[3'-diethylamino-7'- dimethylamino-benzo(c )-1 l '-oxy-xanthenyl l-4-chloropyridine-carboxylic acid-(2) lactone and 2-l3" diethylamino-7-dimethylamino-benzo(c)-l l '-oxyxanthenyl]-4-chloro-pyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a purplish blue color immediately after the solution was adsorbed on acid clay.

(No. 8-b) A mixture comprising 3-[ 3-diethylamino-7'- dimethylamino-benzo(c)-l l '-oxy-xanthenyl 1-4- methyl-pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7 -dimethylamino-benzo( c )-l l '-oxyxanthenyll-4-methyl-pyridine-carboxylic acid-(3) lac: tone. A solution of this mixture in benzene developed a purplish blue color immediately after the solution was adsorbed on acid clay.

(No. 8-c) A mixture comprising 3-[3-diethylamino-7- dimethylamino-benzo(c)-l l '-oxy-xanthenyl 1-6- phenyl-pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7 '-dimethylamino-benzo( c )-l l '-oxyxanthenyl ]-6-phenyl-pyridine-carboxylic acid-( 3) lactone. A solution of this mixture in benzene developed a purplish blue color immediately after the solution was adsorbed on acid clay.

EXAMPLE 9 3.1 g of an isomer mixture comprising 3-[2-ethoxy- 4'-diethylamino-benzoyll-pyridine-carboxylic acid-( 2 and 2-[2'-ethoxy-4'-diethylamino-benzoyll-pyridinecarboxylic acid-(3) having a melting point of 245 to 253C obtained in a similar manner to Example I and L6 g of 5-propionamido-2-naphthol were added to 30 g of 95% sulfuric acid, and the mixture was allowed to react at a temperature of from 95 to lC for hours. After completion of the reaction, the reaction product was poured into l50 ml of ice-water. and dilute aqueous sodium hydroxide was added to the resulting solution while stirring to adjust a pH to about 11. 70 ml of benzene was then added to the mixture to transfer the pyridinecarboxylic acid lactone into the benzene layer which was then separated. The benzene was distilled off from the benzene layer, and the resulting residue was washed successively with water and a small amount of ligroin, and dried to give 3.7 g of an isomer mixture comprising 3-[ 3 '-diethylamino-7 '-propionamidobenzo(c)-1 1-oxy-xanthenyll-pyridine-carboxylic acid- (2) lactone and 2-[3'-diethylamino-7'-propionamidobenzo( c )-l l'-oxy-xanthenyl l-pyridine-carboxylic acid- (3) lactone as light brown colored crystals having a melting point of 231 to 236C. A solution of the above crystals in toluene developed a red color immediately after the solution was adsorbed on acid clay.

EXAMPLE 2.5 g of the isomer mixture of pyridine-carboxylic acid lactone having a melting point of 239 to 242C designated as No. 3-d was dissolved in a mixture of 50 ml of benzene and 0.7 g of triethylamine, and 1.2 g of toluoyl chloride was added to the resulting solution. The mixture was then allowed to react for 5 hours at a temperature of from 65 to 70C followed by allowing the mixture to cool to room temperature. The reaction product thus obtained was then washed with 50 ml of ice-water. and the benzene was distilled off to leave a residue. The resulting residue was then washed with a smal amount of petroleum ether and dried to obtain 3.2 g of an isomer mixture comprising 3-[3 '-diethylamino- 7 '-(4 '-methyl)-benzamido-benzo-(c )-1 1 '-oxyxanthenyll-pyridine-carboxylic acid-(2) lactone and 2-[ 3 '-diethylamino-7 4' '-methyl )-benzamidobenzo(c)-l l-oxy-xanthenyll-pyridine-carboxylic acid- (3) lactone as light reddish purple colored crystals having a melting point of 157 to l64C. A solution of the above crystals in benzene developed a red color immediately after the solution was adsorbed on acid clay.

EXAMPLE I l 2.5 g of the isomer mixture of pyridine-carboxylic acid lactone having a melting point of 239 to 242C obtained in a similar manner as described in Example l0 was dissolved in a mixture of 50 ml of benzene and 0.7 g of triethylamine, and each of the acid halides l l compounds) listed in Table 3 below was added to the resulting solution followed by allowing the mixture to react for 5 hours at a temperature of from 65 to 70C. After completion of the reaction, the reaction mixture was worked up in the same manner as described in Example ]0 to obtain the following lactone in each instance. (The sample number of the resulting lactone is shown in parentheses.)

(No. ll-a) A mixture comprising 3-{3-diethylamino-7- acrylamidobenzo(c)-l l '-oxy-xanthenyl]-pyridinecarboxylic acid-(2) lactone and 2-[3'-diethylamino-7- acrylamido-benzo(c)-l l '-oxy-xanthenyl]-pyridinecarboxylic acid-(3) lactone.

(No. l l-b) A mixture comprising 3-[3'-diethy1amino-7'- benzamido-benz0(c )-l l '-oxy-xanthenyl l-pyridinecarboxylic acid-(2) lactone and 2-[3'-diethylamino-7- 5 benzamido-benzo(c)-l l '-oxy-xanthenyl]-pyridinecarboxylic acid-( 3) lactone. (No. 11-6) A mixture comprising 3-[3'-diethylamino-7-(2",4"-

dimethyl )-benzamido-benzo(c )-l l'-oxy-xanthenyl pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7'-(2",4"-dimethyl)- benzamidobenzo(c)-l l '-oxy-xanthenyl]-pyridinecarboxylic acid-(3) lactone. (No. 11-11) A mixture comprising 3-[3'-diethylamino-7'-(2"- methoxy)-benzamido-benzo(c)-l 1'-oxy-xanthenyl]- pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7'-(2"-methoxy)-benzamido-benzo(c)- ll'-oxy-xanthenyl]-pyridine-carboxylic acid-(3) lactone.

(No. ll-e) A mixture comprising 3-[3'-diethylamino-7-(3"- dimethylamino)-benzamido-benzo(c)-l l'-oxyxanthenyl]-pyridine-carboxylic acid-(2) lactone and 2[ 3 '-diethylamino-7'-( 3 '-dimethylamino benzamido-benzo(c)-l l '-oxy-xanthenyl]-pyridinecarboxylic acid-(3) lactone.

(No. ll-f) A mixture comprising 3-[3'-diethylamino-7'- (3",4",5 "-trioxy )-benzamido-benzo(c)-l 1'-oxyxanthenyl]-pyridine-carboxylic acid-(2) lactone and 2-[ 3'-diethylamino-7-( 3' ',4",5 "-trioxy)-benzamidobenzo(c)-l l'-oxy-xanthenyll-pyridine-carboxylic acid (3) lactone.

A mixture comprising 3-[3'-diethylamino-7'-(4"- nitro)-benzamido-benzo(c)-l l'-oxy-xanthenyl]-pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7 -(4' '-nitro)-benzamido-benzo(c )-l loxy-xanthenyl]-pyridine-carboxylic acid-(3) lactone. (No. ll-h) A mixture comprising 3-[3'-diethylamino-7 '-(2",4"- dichloro)-benzamido-benzo(c)-l l '-oxy-xanthenyl]- pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7 2 ,4 '-dichloro)-benzamidobenzo(c)-l l'-oxy-xanthenyll-pyridine-carboxylic acid- (3) lactone.

(No. ll-i) A mixture comprising 3-[3'-diethylamino-7'- cinnamamido-benzo(c)- I l '-oxy-xanthenyl I-pyridinecarboxylic acid-(2) lactone and 2-[3'-diethylamino-7'- cinnamamido-benzo(c )-l l '-oxy-xanthenyll-pyridinecarboxylic acid-( 3) lactone.

(No. ll j) A mixture comprising 3-[3'-diethylamino-7'-(4"- dimethylamino)-cinnamamido-benzo(c )-l l '-oxyxanthenyl]-pyridine-carboxylic acid-(2) lactone and 2-[ 3'-diethylamino-7 4"-dimethylamino)- cinnamamido-benzo(c )-l l '-oxy-xanthenyl I-pyridinecarboxylic acid-( 3) lactone.

(No. ll-k) A mixture comprising 3-[3'-diethylamino-7'-(l"- naphthoyl )-amino-benzo(c )-l l '-oxy-xanthenyl l-pyridine-carboxylic acid-(2) lactone and 2-[3'- diethylamino-7 l "-naphth0y|)-amino-benzo( c )-l l oxy-xanthenyll-pyridine-carboxylic acid-(3) lactone.

Table 3 Sample Acid Halide Used and Amount Yield Melting Color of Color Developed No. Point Crystals on Acid Clay (Solvent: Toluene) (g) is) (Cl No.1 l-a Acryloyl chloride 0.6 2.7 pale brown reddish purple No.1 l-b Benzoyl chloride 1.0 3.0 165-169 pale pink reddish purple No.1 1 c 2.4Dimethyl-henzoyl chloride 1.2 3.1 pale pink reddish purple No.1 l-d Z-Methoxy-henmyl chloride 1.2 3.0 152-155 pale whireddish purple tish pink No.1 l e 3-Dimethylamino-benzoyl 1.3 3. 136-139 pale pink reddish purple chloride No. l l f 3.4.5-Trioxy-henzoyl chloride L3 3.2 pale redreddish purple dish purple No.1 l-g 4-Nitro-benzoyl chloride 1.2 3.1 171-174 pale yellow reddish purple No.1 l-h 2,4-Dichloro-henzoyl chloride 1.4 3.4 163-167 pale pink reddish purple No.1 1 i Cinnamoyl chloride l.2 3.l 218-225 pale brown reddish purple No.1 1 y 4-Dimethylamino-cinnamoyl 1.5 3.3 pale brown reddish purple chloride No.1 l k lNaphthoyl chloride 1.3 3. pale pink reddish purple EXAMPLE 12 3.2 g of the isomer mixture of benzoyl-pyridinecarboxylic acid having a melting point of 245 to 253C obtained in a similar manner as described in Example 1 and 2.7 g of 4-amino-1-naphthol were added to 26 g of 98% sulfuric acid. The resulting mixture was allowed to react for hours at a temperature of from 90 to 95C and then allowed to cool to room temperature followed by working up in the same manner as described in Example 2 to obtain 2.8 g of an isomer mixture comprising 3-[3'-diethylamino-9-amino-benzo(a)-l l oxy-xanthenyl]-pyridinecarboxylic acid-(2) lactone and 2-[3-diethylamino-9'-amino-benzo(a)-l l-oxyxanthenyl]-pyridine-carboxylic acid-(3) lactone as light yellowish brown crystals having a melting point of N-methyl-N-phenyl-m-anisidine were dissolved in 80 ml of benzene, and 18.8 g of anhydrous aluminum chloride was added to the solution with stirring over about 20 minutes at a temperature of from 20 to C. After completion of the addition. the resulting mixture was allowed to react for 4 hours at a temperature of from 45 to 50C and the reaction mixture was allowed to cool to room temperature. The benzene was removed by decantation, and the resulting reaction product was poured into 300 ml of ice-water followed by stirring. The precipitated solid was filtered, washed successively with water and a small amount of methanol and dried to obtain 13.6 g of an isomer mixture comprising 3-[ 2'- methoxy-4'-(N-methyl-N-phenyl)-amino-benzoyl]- pyridine-carboxylic acid-(2) and 2-[2'-methoxy-4'-(N- methyl-N-phenyl )-amino-benzoyl ]-pyridine-carboxylic acid-(3) as ligh brown crystals having a melting point 224 to 231C. 35

2.5 g of the resulting isomer mixture of pyridineof from 205 to 217 C. If desired, the crystals thus obcarboxylic acid lactone (m.p., 224-231C) was then tained was purified by recrystallization. reacted with each of the acid halides listed in Table 4 3.6 g of the above isomer mixture of benzoyl-pyriin a similar manner as described in Example 10 to obdine-carboxylic acid (m.p.. 205 217C) and 2.3 g of tain the following lactone in each instance. (The sam- 5-acetamido-2-naphthol were added to 17 gof98% sulple number of the resulting lactone is shown in parenfuric acid, and the mixture was allowed to react for 4 theses.) hours at a temperature of from 95 to 100C followed (No. 12-0) by allowing to cool to room temperature. The reaction A mixture comprising 3-[3'-diethylamino-9'- product thus obtained was then worked up in the same acetamido-benzo(a)-1 1'-oxy-xanthenyll-pyridinemanner as described in Example 9 to obtain 3.4 g of an carboxylic acid-(2) lactone and 2-I3'-diethylamino-9- isomer mixture comprising 3-l3'-(N-methyl-N- acetamido-benzo(a)-l 1 '-oxy-xanthenyll-pyridinephenyl)-amino-7 '-acetamido-benzo(c)-l l '-oxycarboxylic acid-(3) lactone. xanthenyl]-pyridine-carboxylic acid-(2) lactone and (No. l2-b) 2-[3'-(N-methyl-N-phenyl)-amino-7'-aeetamido- A mixture comprising 3-[3'-diethylamino-9'-(2"- benzo(c)-l 1'-oxy-xanthenyll-pyridine-carboxylic acidmethyl-5"-chloro)-benzamido-benzo(a)-l 1 '-oxy- (3) lactone as light pink colored crystals having a meltxanthenyll-pyridine-carboxylic acid-(2) lactone and ing point of 231 to 236C. A solution of the above 2-[3-diethylamino-9-(2"-methy1-5"-chloro)- crystals in toluene developed a red color immediately benzamido-benzo(a)-l l-oxy-xanthenyll-pyridineafter the solution was adsorbed on a phenol-aldehyde carboxylic acid-(3) lactone. polymer.

Table 4 Sample Acid Halide Used and Amount Yield Melting Color of Color Developed No. Point Crystals on Acid Clay (Solvent: Toluene) (g) (g) cc) No.12-a Acetyl chloride 0.5 27 246-253 whitish reddish brown No.12-b 2-Methyl-5-chlorobenzoy1 1.3 3.0 183-187 gzjz pink reddish brown chloride EXAMPLE l3 EXAMPLE 14 7.0 g of quinolinic anhydride and 14.1 g of 5.0 of quinolinic anhydride and 14.2 g of N,N-dibenzyl-m-anisidine were added to 60 ml of benzene, and 13.4 g of anhydrous aluminum chloride was added with stirring over about 30 minutes at a temperature of from 20 to 35C. After completion of the addition, the mixture was allowed to react for 4 hours at a temperature of from 45 to 55C and allowed to cool to room temperature. The reaction product thus obtained was then worked up in the same manner as described in Example 13 to obtain 10.6 g of an isomer mixture comprising 3- l2'-methoxy-4'-dibenzylaminobenzoyl ]-pyridinecarboxylic acid-(2) and 2-[2'-mcthoxy-4- dibenzylamino-benzoyl]-pyridine-carboxylic acid-(3) as light brown crystals having a melting point of 195 to 203C. If desired, the resulting crystals were purified by recrystallization.

worked up in the same manner as described in Example 9 to obtain the following lactone. (The sample number of the resulting lactone is shown in parentheses.) (No. lS-a) mixture comprising 3-{3-methylamino-7'- acetamido-benzo(c)-l l -oxy xanthenyl]-pyridinecarboxylic acid-(2) lactone and 2-[3'-methylamino-7'- acetamido-benzo(c)-l l -oxy-xanthenyl l-pyridinecarboxylic acid-(3) lactone.

10 (No. -h)

l5 carboxylic acid-(3) lactone.

Table 5 Sample Naphthalene Compound Used and Amount Yield Melting Color of Color Developed No Point Crystals on Acid Clay (Solvent: Toluene) (g) (g) (C) I No.15-a S-Acetamido-Z-methoxy- 2.4 2.8 pale green reddish purple naphthalene No.15-b 4-Benzamido-lnaphthol 3.0 3.4 pale pink red 4.5 g of the above isomer mixture of benzoyl-pyri- EXAMPLE l6 dine-carboxylic acid (mp, 195 203C) and 2.3 g of 5-acetamido-2-naphthol were added to g of 98% sulfuric acid, and the mixture was allowed to react for 5 hours at a temperature of from 90 to 100C followed by allowing to cool to room temperature. The reaction product thus obtained was then worked up in the same manner as described in Example 9 to obtain 3.8 g of an isomer mixture comprising 3-[3'-dibenzylamino-7'- acetamido-benzo(c)-l l -oxy-xanthenyl]-pyridinecarboxylic acid-(2) lactone and 2-[3'-dibenzylamino- 7'-acetamido-benzo(c )-l l '-oxy-xanthenyl l-pyridinecarboxylic acid-(3) lactone as pale pink colored crystals having a melting point of 226 to 231C. A solution of the above crystals in benzene developed a red color immediately after the solution was adsorbed on acid clay.

EXAMPLE 15 4.5 g of quinolinic anhydride and 4.0 g of 3- methylaminophenol were dissolved in 60 ml of benzene, and 10.9 g of anhydrous aluminum chloride was added to the solution with stirring over about 20 minutes at a temperature of from 20 to C. After com pletion of the addition, the resulting mixture was allowed to react for 5 hours at a temperature of from 40 to C and the resulting reaction mixture was allowed to cool to room temperature. The reaction product was 5- then worked up in the same manner as described in Ex- Each of (a) 4-chloroquinolinic anhydride, (b) 4- methylquinolinic anhydride and (c) o-phenyl- 30 quinolinic anhydride in place of quinolinic anhydride used in Example 1 was reacted with N,N-diethyl-mphenetidiene in the same manner as described in Example 1 to obtain the following corresponding pyridinecarboxylic acid in each instance.

35 a. an isomer mixture comprising 3-(2'-ethoxy-4'- diethylaminobenzoyl)-4-chloro-pyridinecarboxylic acid-( 2) and 2-(2'-ethoxy-4'- diethylamino-benzoyl)-4-chloro-pyridinecarboxylic acid-(3 40 b. an isomer mixture comprising 3-(2'-ethoxy-4'- diethylamino-benzoyl)4-methyl-pyridine carboxylic acid-(2) and 2-(2'-ethoxy-4'- diethylamino-benzoyl)-4-methyl-pyridinecarboxylic acid-( 3 and c. an isomer mixture comprising 3-(2-ethoxy-4'- diethylamino-benzoyl)-6-phenyl-pyridinecarboxylic acid-(2) and 2-(2-ethoxy-4'- diethylamino-benzoyl)-6-phenyl-pyridinecarboxylic acid-(3).

Each of the isomer mixtures of pyridine carboxylic acid thus obtained was then reacted with S-acetamido- 2-naphthol followed by working up in the same manner as described in Example 9 to obtain the following corresponding pyridine-carboxylic acid lactone in each instance.

(No. l6-a) A mixture of 3-13'-diethylamino-7-acetamidobenzo(c)-1 l'-oxy-xanthenyl l-4-chloro-pyridinecarboxylic acid-(2) lactone and 2-[3-diethylamino-7'- acetamido-benzo(c)-l l '-oxy-xanthenyll-4-chloropyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a reddish purple color immediately after the solution was adsorbed on acid clay.

A mixture of 3-13-diethylarnino-7'-acetamido benzo( c)-l l'-oxy-xanthenyl l4-methyl-pyridine- 25 carboxylic acid-(2) lactone and 2-{3'-diethylamino-7'- acetamido-benzo(c)-l l -oxy-xanthenyl1-4-methylpyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a reddish purple color immediately after the solution was adsorbed on acid clay. (No. 16-() A mixture of 3-[3'-diethylamino-7'-acetamidobenzo(c)-1 l oxy-xanthenyll-6-phenyl-pyridinecarboxylic acid-(2) lactone and 2-[3-diethylamino-7- acetamido-benzo(c)-l l'-oxy-xanthenyl l-o-phenylpyridine-carboxylic acid-(3) lactone. A solution of this mixture in benzene developed a reddish purple color immediately after the solution was adsorbed on acid clay.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

What is claimed is:

1. A lactone compound represented by the following formula N f I RZ/ CI,

o i= g0 5 N R IA or a mixture thereof, wherein R1 represents a hydrogen atom, a lower alkyl group or a benzyl group, R represents a lower alkyl group, a benzyl group or an unsubstituted or substituted phenyl group wherein the substituent is a lower alkyl group or a halogen atom, R represents a hydrogen atoms, a lower alkyl group, a halogen atom or a phenyl group, and the partial structure represents a naphthalene residual group of the formula (lVa) or (lVb) (IVb) (Iva) wherein R represents a hydrogen atom. a lower alkyl group, a lower alkoxy group, a halogen atom, an amino group, a mono-lower alkylamino group, di-lowcr alkylamino group. a monobenzylamino group, a diben zylamino group, an N-lower alkyl-N-benzylamino group, an anilino group, an N-lower alkylanilino group, a NHCOX group wherein X represents a lower alkyl group, a lower alkenyl group, or an unsubstituted or substituted styryl group, an unsubstituted or substituted phenyl group or an unsubstituted or substituted naphthyl group wherein the substituent is a lower alkyl group, a lower alkoxy group, a di lowcr alkylamino group, a hydroxy group, a nitro group or a halogen atom and said lower alkyl, alkoxy and alkenyl groups have I to 5 carbon atoms.

2. A process for preparing a lactone compound of the formula or a mixture thereof, wherein R represents a hydrogen atom, a lower alkyl group or a benzyl group, R represents a lower alkyl group, a benzyl group or an unsubstituted or substituted phenyl group wherein the substituent is a lower alkyl group or a halogen atom, R represents a hydrogen atom, a lower alkyl group, a halogen atom or a phenyl group, and the partial structure represents a naphthalene residual group of the formula (lVa) or (lVb) (Iva) (lVb) wherein R represents a hydrogen atom, a lower alkyl group. a lower alkoxy group, a halogen atom, an amino group. a mono-lower alkylamino group, di-lower alkylamino group, a monobenzylamino group, a dibenzylamino group. an N-lower alkylN-benzy1amino group, an anilino group, an N-lower alkyl anilino group. a -NHCOX group wherein X represents a lower alkyl group. a lower alkenyl group, or an unsubstituted or substituted styryl group. an unsubstituted or substituted phenyl group or an unsubstituted or substituted naphthyl group wherein the substituent is a lower alkyl group, a lower alkoxy group, a di-lower alkylamino group. a hydroxy group, a nitro group or a halogen atom and said lower alkyl, alkoxy and alkenyl groups have 1 to 5 carbon atoms. which comprises condensing a benzoyhpyridine-carboxylic acid represented by the formula (110) or (llb) or a mixture thereof, wherein R,, R and R are as defined above. and R represents a hydrogen atom or a lower alkyl group. with a naphthalene compound represented by the formula (III) (III) 095 wherein R represents a hydrogen atom or a lower alky group and the OR group is substituted on 1- or 2- position of the naphthalene ring, and R is as definec above, at a temperature in the range of from to 130C for a period of from about 2 to about 10 hours in the presence or absence of a volatile inert organic solvent.

3. The process according to claim 2, wherein said condensing agent is concentrated sulfuric acid, acetic anhydride, phosphorus pentachloride, phosphorus oxy- (VIIIa) (VIIIb) or a mixture thereof, wherein R, represents a hydrogen atom. a lower alkyl group or a benzyl group, R represents a lower alkyl group, a benzyl group or an unsubstituted or substituted phenyl group wherein the substituent is a lower alkyl group or a halogen atom, R represents a hydrogen atom, a lower alkyl group, a halogen atom or a phenyl group, and the partial structure represents a residue of a naphthalene compound of the formula (lXa) or (lXb) NHCO-X NBC 0- X (1Xa) (lxb) wherein X represents a lower alkyl group, a lower alkenyl group, or an unsubstituted or substituted styryl group, an unsubstituted or substituted phenyl group or an unsubstituted or substituted naphthyl group wherein the substituent is a lower alkyl group, a lower alkoxy group, a di-lower alkylamino group. a hydroxy group, a nitro group or a halogen atom and said lower alkyl, alkoxy and alkenyl group have 1 to 5 carbon atoms,

which comprises condensing a pyridine-carboxylic acid lactone represented by the formula wherein R R and R are as defined above, and the partial structure,

represents naphthylamine of the formula (Via) or (Vlb) (Vla) (Vlb) with an acid halide represented by the formula (VII) x-co v (vm wherein X is as defined above and Y represents a halogen atom, in a volatile inert organic solvent at a temperature in the range of from about 40 to about l [0C for a period of from about 2 to about 8 hours in the presence of an acid acceptor.

7. The process according to claim 6, wherein said volatile inert organic solvent is chloroform, benzene. toluene or chlorobenzenes.

8. The process according to claim 6, wherein said acid acceptor is triethylamine, pyridine, dimethylamine. sodium bicarbonate or sodium carbonate.

9. The process according to claim 6, wherein said acid acceptor is used in an amount of from about 1.0 to 1.5 moles per 1 mole of said pyridinecarboxylic acid lactone. 

1. A LACTONE COMPOUND REPRESENTED BY THE FOLLOWING FORMULA
 2. A process for preparing a lactone compound of the formula
 3. The process according to claim 2, wherein said condensing agent is concentrated sulfuric acid, acetic anhydride, phosphorus pentachloride, phosphorus oxychloride, phosphoric acid, polyphosphoric acid, zinc chloride, stannic chloride or aluminum chloride.
 4. The process according to claim 2, wherein said volatile inert organic solvent is chloroform, tetrachloroethane, benzene or chlorobenzenes.
 5. The process according to claim 2, wherein said napthalene compound is used in an amount of from about 1.0 to about 1.5 moles per 1 mole of said benzoyl-pyridine-carboxylic acid or a mixture thereof.
 6. A process for preparing a lactone compound represented by the formula
 7. The process according to claim 6, wherein said volatile inert organic solvent is chloroform, benzene, toluene or chlorobenzenes.
 8. The process according to claim 6, wherein said acid acceptor is triethylamine, pyridine, dimethylamine, sodium bicarbonate or sodium carbonate.
 9. The process according to claim 6, wherein said acid acceptor is used in an amount of from about 1.0 to 1.5 moles per 1 mole of said pyridine-carboxylic acid lactone. 